[PATCH] dma-buf: cma_heap: Fix mutex locking section

[Weizhao Ouyang]

Fix cma_heap_buffer mutex locking critical section to protect vmap_cnt
and vaddr.

Fixes: a5d2d29e24be ("dma-buf: heaps: Move heap-helper logic into the cma_heap 
implementation")
Signed-off-by: Weizhao Ouyang <o451686...@gmail.com>
---
 drivers/dma-buf/heaps/cma_heap.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 0c05b79870f9..83f02bd51dda 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -124,10 +124,11 @@ static int cma_heap_dma_buf_begin_cpu_access(struct 
dma_buf *dmabuf,
        struct cma_heap_buffer *buffer = dmabuf->priv;
        struct dma_heap_attachment *a;
 
+       mutex_lock(&buffer->lock);
+
        if (buffer->vmap_cnt)
                invalidate_kernel_vmap_range(buffer->vaddr, buffer->len);
 
-       mutex_lock(&buffer->lock);
        list_for_each_entry(a, &buffer->attachments, list) {
                if (!a->mapped)
                        continue;
@@ -144,10 +145,11 @@ static int cma_heap_dma_buf_end_cpu_access(struct dma_buf 
*dmabuf,
        struct cma_heap_buffer *buffer = dmabuf->priv;
        struct dma_heap_attachment *a;
 
+       mutex_lock(&buffer->lock);
+
        if (buffer->vmap_cnt)
                flush_kernel_vmap_range(buffer->vaddr, buffer->len);
 
-       mutex_lock(&buffer->lock);
        list_for_each_entry(a, &buffer->attachments, list) {
                if (!a->mapped)
                        continue;
-- 
2.32.0